Rivet feeding apparatus



Aug. 27, 1963 Filed Jan. 17, 1961 C. E. BREWER RIVET FEEDING APPARATUS 3Sheets-Sheet 1 Aug. 27, 1963 c. E. BREWER RIVET FEEDING APPARATUS 5Sheets-Sheet 2 Filed Jan. 17, 1961 Aug. 27, 1963 'c. E. BREWER RIVETFEEDING APPARATUS 3 Sheets-Sheet 5 Filed Jan. 17, 1961 United StatesPatent 3,101,858 RIVET FEEDING APPARATUS Cliiford Edmund Brewer,Parkstone, Dorset, England (19 Upton Road, Fleets Bridge, Poole, Dorset,Eng- This invention relates to riveting apparatus and more particularlyto an apparatus adapted to handle so called pop rivets. Pop rivets areof the type having a flanged head portion which is adapted to securetogether the articles to be joined and a mandrel portion of mild steelwhich is connected to the head portion. The pop rivetsfurther may be oftwo types; in a first of which the head is pulled through the rivet toupset the same and secure the articles to be joined; and in the secondtype tension is exerted on the mandrel to cause upsetting of the rivetand the mandrel is broken 01f whenthe rivet is installed. Consequently,the mandrel is waste portion and solely facilitates handling andinstallation. Thus it may be said that pop rivets are hollow rivetshaving an axially projecting shank associated therewith in such a mannerthatwith the rivet in position in a workpiece an appropriate tensionexerted on the mandrel will result in upsetting of said rivet and alsoin removal of a portion of said mandrel therefrom, a head portion of themandrel remaining in the hollow rivet. Pop rivets are used extensivelyin the aircraft industry for installations which are accessible-only'firom one side.

According to the invention the riveting apparatus comprises a rotoradapted to carry a plurality ofi chucks in angu'larly spacedrelationship, each such chuck being capable 0t receiving the mandrel ofa pop rivet, means for imparting a step by step motion to said rotorwhereby successive chucks will be moved successively from a feedposition at'which a rivet may be fed thereinto to an operative positionand thence to la mandrel dischargeposition and means adapted when eachchuck is in the operative position to impart a retractive movementthereto sufiicient in the case of use with rivets of the first type toremove the mandrel from the rivet while in the second case sufficienttoupset the rivet and remove a portion of the mandrel. Conveniently therotor will carry hour chucks spaced apart at 90 and the arrangement issuch that on completion of each operative cycle of the apparatus therotor will have been moved through 9i). Preferably means will beprovided whereby on operahon of the apparatus the rivet will be fedautomatically mandrel first into each chuck when the latter is in thefeed position. i

In order that the invention may be clearly understood and readilycarried into eliect one constructional em bodiment thereof will now bedescribed with reference to the accompanying drawings in which:

FIGURE 1 is a front elevational view of a riveting apparatus,

FIGURE 2 shows a section on the line 2- -2 of FIG- URE 1,

FIGURE 3 is a cross sectional view on a larger scale of a rotor assemblyincorporated in the apparatus shown in FIGURES 1 and 2,

FIGURE 4 is a section on the line 44 of FIG- URE 3,

FIGURE 5 is a sectional view on yet a larger scale illustrating theconstruction of a chuck incorporated in the aforesaid rotor assembly,

FIGURE 6 is a perspective View of a rivet feed mechanism which ismounted at the upper part of the apparatus illustrated in FIGURE 1,

ice

FIGURE 7 is a front elevational view of a part of the :feed mechanism,

FIGURES 8, 9 and 10 are plan views of a part of the feed mechanism andillustrate difierent stages in the operation thereof.

Referring now to the drawings Ill denotes a rotor which is supported forrotational movement about the axis-of a horizontal shaft 11. The shaftis supported for free rotation in a rigid frame structure designatedgenerally by 12 such structure being mounted on a base plate 13 which isin turn supported on a table 15. Suspended from the base plate by meansof rods 16 is a lower platform 17 adapted to support. a double actingpneumatic ram 18. Coupled to the ram 18 to be reciprocated verticallythereby is a rack 19 by means of which a step by step-rotationalmovement will be imparted to the rotor 10 as will be hereinafter madeapparent.

The rotor 10 carries four chuck assemblies designated generally by 20which are spaced apart through relatively to each other, thelongitudinal axes of the chucks being disposed radially of said rotor.As will be clearly seen from FIGURE 5 each chuck assembly is located ina radially directed slot formed in the rotor Ill and comprises a bodyportion 21 which is slidable axially of the slot and is urged radiallyoutwardly by means of a spring 22. Disposed coaxially within the bodyportion 21 so as to be capable of relative axial movement is a mandrelgripper element comprising a hollow sleeve portion 23 and resilient jaws24 such jaws being externally tapered as shown and adapted to cooperatewith a corresponding tapered seating formed internally of said bodyportion at the outer end thereof. The gripper element is urged forwardlyrelatively to the body portion 21 by means of a light spring 25 so thatthe jaws 24 will be urged into contact with the aforesaid taperedseating. 26 denotes a hollow cap member which is adapted to house theouter end of each chuck assembly, such members, which are so mounted onthe rotor as to be readily removable and replaceable to allow of readychanging of the chucks, each being provided with a threaded bush 27 thebore of which is aligned with the longitudinal axis of the gripperelement to allow passage of a rivet mandrel therethrough and into thelatter. The construction is such that when the body portion 21 is in itsextended position, which is the position which it normally assumes dueto the action of the spring 22, the jaws 24- of the gripper element willbe brought into resilient contact with the inner end of the bush 27. Thearrangement is such that with the jaws 24 in contact with the bush 27there will be slight additional forward movement ofthe body portion 21under the action of the spring 22 so that the tapered seating will bemoved forwardly relatively to said jaws thereby a-llowing them to assumean open position. This relative movement between the body portion 21 andthe jaws 24 will result in compression of the spring 25. This conditionwill prevail in each chuck at all times except when the chuck is in theoperative position and the rack 19 is moving downwardly as will beherein-after more fully described. When the chuck is in such positionwhich is designated B in FIGURE 4 and the rack 19 is moving downwardlythe body portion 21 will as hereinafter described be moved rearwardly sothat the external tapering of the jaws 24 will cooperate with thetapered seating formed internally of said body portion and said jawswill be caused to close and to exert a grip on the rivet mandrel in thechuck. At its inner end the body portion 21 of each chuck assembly isprovided with a transverse pin 28 adapted to project laterally from eachside of the rotor 10. Each pin 23 may be so mounted as to be capable offree rotational movement about its longitudinal axis but preferably afreely rotatable roller as indicated at 29 will be mounted at each endthereof.

Fixedly mounted on the shaft 11 are two circular discs 30, 31 which aredisposed one at each side of the rotor 10. As will be seen from FIGURES3 and 4 each of the discs 30, 31 is formed at its inner face with a camsurface 32 with which the rollers 29 on the pins 28 of the chuckassemblies are adapted to cooperate as will be hereinafter madeapparent. As indicated above the discs 3%, 31 are fixedly mounted on theshaft 11 so that they will move together as a unit and one of suchdiscs, in this case the disc 30, is provided externally with a toothedsector adapted to cooperate with the rack 19.

The arrangement as so far described is such that on downward movement ofthe rack 19 (in all figures it is shown in its uppermost position) thediscs 36), 31 will be moved angularly through 90 (clockwise as seen inFIGURE 4) while on upward movement of said rack said discs will moveangularly in the reverse direction through 90 (counter clockwise asshown in FIGURE 4) back to their initial position.

As will be seen from FIGURE 4 the cam surface 32 on each of the discs30, 31 terminates in a shoulder 33 and referring now to that figure itwill be appreciated that downward movement of the rack 19 will result inangular movement of the discs 30, 31 clockwise. As the discs 30, 31 moveclockwise the cam surfaces 32 will cause the pin 23 and hence the bodyportion 21 of the chuck at position B to be retracted so that thegripper jaws 24 of that chuck will become operative to grip and exert apull on the mandrel of a rivet present therein to secure the rivet inthe work and also to remove the mandrel therefrom. As the rack 19reaches the end of its downward movement the rollers 29 on the pin 23 ofthe chuck at position B will pass over the shoulders 33 and the spring22 will be eifective to move the chuck assembly forwardly back to itsinitial extended position wherein the resilient jaws 24 will again beopened. In this position the shoulders 33 on the discs 30, 31 will belocated behind the chuck assembly at position B so that on upwardmovement of the rack 19 with consequent counter clockwise rotation ofthe discs 30, 31 the rotor will then move with said discs through 90 sothat the chuck assembly that was at position B will then be located atposition C, at which point the mandrel previously removed at position Bwill fall by gravity from the chuck.

It may be mentioned here that rivet will be fed into a chuck at positionA by apparatus hereinafter described, at position B the rivet will besecured in the work and the mandrel removed by the closing andsubsequent retraction of jaws 24-, and at position C the spent mandrelwill be ejected, the fourth position D being an idle position as far aseach chuck assembly is concerned.

34 denotes a spring loaded stop which is adapted to cooperate in turnwith the projecting cap elements 26 of the chuck assemblies on the rotor10 in order positively to prevent any tendency of reverse rotationalmovement of the rotor. Thus stop 34 prevents clockwise movement as shownin FIG. 4, of the rotor during downward movement of the rack 19' asfollows. During each desired angular movement of the rotor on upwardtravel of said rack one of the cap elements 26 will, move past thespring loaded stop 34 as the rack reaches the limit of its upwardmovement. The stop 34 immediately snaps into an operative position inthe path of element 26 to prevent reverse angular movement of the rotor.

35 denotes a spring which is adapted to cooperate in turn with theprojecting cap elements 26 of the chuck assemblies in order to preventany tendency to over-running of the rotor on each 90 angular movementthereof. The spring 35 is mounted on an arm 36 which is connected to therack 19 by any suitable means so long as the arm will move with the rackand will only be located in its operative position at appropriate times.The spring 35 therefore engages the cap element 26 and is of sufiicientstrength to prevent more than a movement of element 26.

Mounted on the aforesaid arm 36 is an upwardly projecting cam rod 37carrying two cams 38 and 39 adapted to operate a rivet feed mechanism ashereinafter described. As indicated above the arm 36 is connected to therack 19 so that the cam rod 37 will be reciprocated vertically with thelatter and will thus be effective to actuate the feed mechanism in timedrelation with the remainder of the apparatus so that as each chuckassembly reaches the position A a rivet will be fed theretoautomatically. The rod 37 is conveniently provided with a longitudinallyextending slot 40 in which a stationary pin, indicated at 41 in FIG. 2,is adapted to engage. The pin 41 is supported in the rigid framestructure and the arrangement is such that said rod will be effectivelyguided and maintained in a vertical path.

In the embodiment illustrated the rivet feeding mechanism comprises ahopper 42 adapted to hold a bulk supply of rivets such rivets being fedsuccessively from said hopper down an inclined feed-way 43 one behindthe other. The feedway essentially comprises two plates in spacedparallel relation with the mandrels of the rivets being accommodated inthe space between the plates while the flanges on the heads of therivets rest on and slide along the inclined edges of said plates.Disposed at the lower end of the feedway and slidable transverselyrelatively thereto into and out of an operative position wherein it willclose the latter is a gate 44 such gate comprising an upstanding stripon a slide bar 45. At its rear end the slide bar 45 is provided with anupstanding lug 46 adapted to cooperate with the cam 39 on the rod 37. Atits upper end the lug 46 carries a transverse bar with two laterallyprojecting lugs 47 adapted to provide anchorages for one end of each oftwo coiled tension springs 48, 49. The other ends of the springs 48-49are anchored to laterally projecting lugs 50 carried by a transverse baron an upstanding lug 51 on a second slide bar 52 which carries at itsouter end a retaining and position block 53. The lug 51 on the slide bar52 is adapted to cooperate with the cam 38 on the rod 37 and it will beappreciated that the springs 43, 49 serve to maintain the lugs 46, 51 incontact with the respective cam surfaces 39, 38 on said rod. As will beseen from FIGURES 7, 9 and 10 the gate 44 is provided at its lower endwith an out-turned lip 54 the purpose of which will be hereinafter madeapparent.

The construction is such that when the rack 19 and hence the cam rod 37are in their uppermost positions the gate 44 will be retracted due tothe fact that the lug 46 on the slide bar 45 will be forced rearwardlyby reason of the fact that it is then in contact with an increasedthickness of said rod 37. Simultaneously the retaining and positionblock 53' will be in its advanced position by virtue of the fact thatthe lug 51 on the slide bar 52 is also in engagement with an increasedthickness of the rod 37. This position is illustrated in FIGURES 7 and 8and in such position a rivet will pass from the feedway 43 into theposition shown in FIGURES 7 and 8 wherein the head of the rivet willengage and be supported by the block 53. As the rack 19 and hence thecam rod 37 move downwardly the gate will by reason of the relativepositioning of the cam surfaces 38, 39 commence to move forwardly toshut off the feedway prior to there being any relative movement of theblock 53 so that the rivet will still be supported as shown in FIGURE 7.With continued downward movement of the rack *19 and of the cam rod 37the gate 44 will move progressively forwardly while the block 53 willmove rearwardly as shown in FIGURES 9 and 10. At a predetermined pointthe block 53 will be moved clear of the head of the rivet which willthen drop downwardly into the feed position wherein it will hangvertically with the flange on its head supported on the lip 54 of thegate 44. The arrangement is such that as the rivet falls into the feedposition its mandrel will enter that chuck which is then at position Ait being and to snap off and remove the mandrel.

understood that such chuck will have been brought to position A on theprevious upward movement of the rack 19 there being no angular motion ofthe rotor on downward movement of said rack. When the rack 19 and thecam rod 37 are in their lowermost positions the gate 44- and the block53 will be respectively fully projected and retracted as indicated inFIGURE 10. On upward movement of the rack 19 and the cam rod 37' therewill by reason of the shaping of the cam 38 and 39 initially be nomovement of the slide bars 45 and 52 and hence of the gate 44, and block53. However the rotor will move angularly and hence the chuck into whichthe rivet was fed will move from position A towards position B therebyremoving the rivet from the feed mechanism. As the rack 19 and cam rod37 continue to rise the slide bars 45 and 52 will be respectivelyretracted and projected so that at the end of the upward stroke the gate44 will be fully retracted to allow passage of another rivet from thefeedway 43 while the block 53 will be fully projected and will beeffective to support such rivet as shown in 'FIG- URE 7. It will beappreciated that upon completion of the upward stroke of the rack 19another chuck will have been brought into position A but as explainedabove actual feeding of the rivet into the chuck will not take placeuntil the rack 19 and the cam rod 37 again move downwardly.

If desired a small spring such as is indicated at 55 may be provided inorder to prevent undesired displacement of the rivet mandrels duringfeeding, such spring being strong enough merely to hold the rivet butnot provide any resistance to removal of the same on rotation of therotor. 56 denotes a slotted guide which will be engaged by the upperportions of the rivet heads as they reach the lower end of the feedwayand will serve to maintain the rivets in the required position.

The apparatus above described is adapted to operate as follows.

On downward movement of the rack 19 a rivet will be fed into the chuckon the rotor which is at position A. Simultaneously the chuck atposition B will be retracted to secure the rivet which is presenttherein in the work, On upward movement of the rack 19 the rotor will berotated through 90 to bring the chuck previously at position A intoposition B such chuck carrying with it the rivet fed thereto by the feedmechanism. With this rotation another chuck will be brought into therivet receiving position. With the newly loaded chuck at position Bdepression of the rack 19 and of the cam rod 37 will result in securingof the rivet and removal of the mandrel and in feeding of a rivet intothe chuck then at position A. The next upward movement of said rackwould result in bringing the chuck previously at position B intoposition C whereat the spent mandrel will fall from the chuck under theaction of gravity. Thus during operation of the machine the rotor willhave a step by step motion imparted thereto bringing the chuckssuccessively from position A to B, thence to C and D and again to A andso on, the cycle being repetitive as long as the ram 18 is kept inoperation. Furthermore it will be appreciated that each chuck will besupplied with a rivet at A and, will be operative to secure the rivet inthe work at B and will discharge the spent mandrel at C.

Conveniently the machine may be provided with a bracket as indicated at57 to form a locating means for Work to which rivets are to be applied.

What is claimed is:

1. Apparatus for setting rivets of the type having a mandrel, saidapparatus comprising a plurality of chucks each including a pair of jawsnormally spaced apart, a rotor supporting said chucks in angularlyspaced relationship, each of said chucks being adapted for receiving themandrel of one of said rivets between the jaws thereof, means forimparting a step by step motion to said rotor whereby said chucks aremoved successively from a feed position at which one of said rivets isfed thereinto, to an operative position and thereafter to a mandreldischarge position, and means synchronized with the means for impartingthe step by step motion for clamping the jaws of said chucks together inthe operative position to grip the mandrel of a rivet in the respectivejaws while applying a tension force to said mandrel to remove themandrel from the rivet to provide a setting of the rivet.

2. Apparatus as claimed in claim 1 in which the rotor is mounted forfree rotation and comprising cam means operatively coupled to said rotorand said chucks to retract said chucks in the operative position withthe cam means rotating in a first angular direction and said rotormaintained at rest, while reverse angular movement of said cam meansresults in a corresponding angular movement of said rotor.

3. Apparatus as claimed in claim 2 wherein the cam means comprises apair of disc members, each being disposed at opposite sides of the rotorand coaxial therewith, each of said members having an inner surface andcam track provided therein, follower means on each of said chucks inoperative engagement with said cam tracks for retracting saidcorresponding chuck.

4. Apparatus as claimed in claim 3 comprising a transverse pin on thebody portion and projecting laterally from opposite sides thereof, saidpin cooperating with the cam tracks of the disc members with saidcorresponding chuck in the operative position.

5. Apparatus as claimed in claim 3 comprising a cap removably attachedto the rotor for each of said chucks and enclosing the same, each ofsaid caps having an aperture therein aligned with the respective chuckand enabling entry of the mandrel therein.

6. Apparatus as claimed in claim 2 wherein the rotor is provided with aradially directed slot for each of said chucks, each of said chucksbeing supported in one of said slots for limited radial movement, andresilient means in each said slot for normally maintaining thecorresponding chuck in extended position.

7. Apparatus as claimed in claim 6 wherein each of said chucks comprisesa body portion which is slidable in the corresponding radially directedslot in the rotor, said jaws constituting mandrel receiving and grippermeans and being located in said body portion, said body portion and jawsdefining cooperating surfaces whereby axial movement of the body portionrelatively to the jaws will result in closure of the jaws.

8. Apparatus as claimed in claim 2 comprising a reciprocable rack, atoothed segment engaging said rack and operatively associated with saidcam means to drive the same.

9. Apparatus as claimed in claim 8 comprising a double acting ramcoupled to said rack for driving the same.

10. Apparatus as claimed in claim 2 comprising resilient stop meanscoupled to said rotor for preventing overrunning of the rotor on eachangular movement thereof.

11. Apparatus as claimed in claim 2 comprising a resilient stopoperatively associated with said rotor to permit rotation of the rotorin a first direction and to positively prevent rotation in the reversedirection.

References Cited in the file of this patent UNITED STATES PATENTS1,357,368 Wilkins Nov. 2, 1920 1,806,217 Rees May 19, 1931 1,997,438Stimpson Apr. 9, 1935

1. APPARATUS FOR SETTING RIVETS OF THE TYPE HAVING A MANDREL, SAIDAPPARATUS COMPRISING A PLURALITY OF CHUCKS EACH INCLUDING A PAIR OF JAWSNORMALLY SPACED APART, A ROTOR SUPPORTING SAID CHUCKS IN ANGULARLYSPACED RELATIONSHIP, EACH OF SAID CHUCKS BEING ADAPTED FOR RECEIVING THEMANDREL OF ONE OF SAID RIVETS BETWEEN THE JAWS THEREOF, MEANS FORIMPARTING A STEP BY STEP MOTION TO SAID ROTOR WHEREBY SAID CHUCKS AREMOVED SUCCESSIVELY FROM A FEED POSITION AT WHICH ONE OF SAID RIVETS ISFED THEREINTO, TO AN OPERATIVE POSITION AND THEREAFTER TO A MANDRELDISCHARGE POSITION, AND MEANS SYNCHRONIZED WITH THE MEANS FOR IMPARTINGTHE STEP BY STEP MOTION FOR CLAMPING THE JAWS OF SAID CHUCKS TOGETHER INTHE OPERATIVE POSITION TO GRIP THE MANDREL OF A RIVET IN THE RESPECTIVEJAWS WHILE APPLYING